1. Field of the Invention
The present invention relates to a resin liquid-crystal cell substrate which serves also as a light pipe and which can form a liquid-crystal display device excellent in reduction of both thickness and weight.
The present application is based on Japanese Patent Application No. Hei. 11-143494, which is incorporated herein by reference.
2. Description of the Related Art
A liquid-crystal display device in which a surface light source constituted by a side light type light pipe is disposed on the visual recognition back surface side (back side) or visual recognition side (front side) of liquid-crystal cells is heretofore known as a transmission type or reflection-transmission dual type liquid-crystal display device. Greater reduction in both thickness and in weight has been, however, eagerly demanded to use the advantage of the liquid-crystal display device effectively with the advance of popularization of the liquid-crystal display device into various kinds of fields. To achieve such greater reduction both in thickness and in weight has been a theme.
An object of the present invention is to achieve greater reduction both in thickness and in weight of a liquid-crystal display device in compliance with the aforementioned demand.
According to the present invention, there is provided a liquid-crystal cell substrate comprising a sheet which has a thickness in a range of from 0.1 to 1 mm and is made of a resin with a glass transition temperature of not lower than 130xc2x0 C. The sheet is provided with light output means on one of upper and lower surfaces of the sheet. Light incident on a side surface is delivered out of the one of the upper and lower surfaces through the light output means. Further, a liquid-crystal cell comprises two cell substrates, and a liquid crystal enclosed in between the two cell substrates, wherein one of the two cell substrates is constituted by the aforementioned liquid-crystal cell substrate. A liquid-crystal display device is constituted by such a liquid-crystal cell.
The cell substrate according to the present invention is light in weight because the cell substrate is made from resin. The cell substrate may be used as a light pipe and as a cell substrate. A side light type light pipe may be formed so as to be used as a surface light source by disposing a light source on a side surface of liquid-crystal cells using such a substrate or on a side surface of the substrate. As a result, the background-art back light or front light can be omitted. A liquid-crystal display device can be formed as an illumination system quite different from the background-art transmission type or reflection-transmission dual type liquid-crystal display device. Greater reduction both in thickness and in weight of the liquid-crystal display device can be achieved.
Features and advantages of the invention will be evident from the following detailed description of the preferred embodiments described in conjunction with the attached drawings.